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This report deals with the construction and the examination of an optical frequency standard based on laser-cooled calcium atoms. An apparatus was built in which calcium atoms were caught from a thermal atom beam in a magneto-optical trap. The transition frequency of the intercombination transition was determined by means of a Ramsey Bordé atom interferometer. A personal computer was used to stabilise the frequency of a laser. Algorithms were developed that largely prevent frequency shifts from appearing. By means of a frequency chain which can be followed by phases, the realised frequency was compared to the primary standard for time and frequency, the caesium atomic watch. Following these investigations, the calcium frequency standard offers the most accurately known frequency in the visible spectrum range.

Additional information

Authors: ZINNER G, Physikalisch- Technische Bundesanstalt, Braunschweig (DE)
Bibliographic Reference: Report: PTB-Opt-58 DE (1998) 106pp.
Availability: Available from Physikalisch Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig (DE)
ISBN: ISBN 3-89701-131-X
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